Quercus obtusata is an oak in the white oak group (Quercus sect. Quercus) endemic to Mexico, with a distribution ranging from San Luis Potosí and Nayarit south to Oaxaca.McVaugh, R. 1974. Flora Novo-Galiciana: Fagaceae. Contributions from the University of Michigan Herbarium 12(1,3): 1–93Romero Rangel, S., E. C. Rojas Zenteno & M. L. Aguilar Enríquez. 2002. El género Quercus (Fagaceae) en el estado de México. Annals of the Missouri Botanical Garden 89(4): 551–593 in Spanish, with line drawings of each species It is native to the southern Sierra Madre Occidental, Trans-Mexican Volcanic Belt, and Sierra Madre del Sur, where it grows in oak forest, pine–oak forest, and the transition to dry shrubland from 1,240 to 2,630 metres elevation. It is often associated with Quercus crassipes, Q. crassifolia, Q. × dysophylla, Q. laeta, and Q. rugosa.
Quercus obtusata is a tree up to tall with a trunk sometimes more than in diameter. The leaves are thick and leathery, up to long, widely egg-shaped with 3–9 pairs of shallow rounded lobes or undulations.Bonpland, Aimé Jacques Alexandre. 1809. Plantae Aequinoctiales 2: 26-27 diagnosis in Latin, description and commentary in FrenchBonpland, Aimé Jacques Alexandre. 1809. Plantae Aequinoctiales 2: plate 76 drawing of Quercus obtusata
Resembles Q. potosina, which has smaller leaves (3–10 x 2–6 cm); also resembles Q. rugosa, this one has a convex leaf strongly coriaceous, a revolute margin, the epidermis bullate; at least, one can differentiate Q. obtusata from Q. laeta, which has foliar underside glaucous, without masses of glandular secretions, none or rare glandular trichomes, a leaf more oblong than oboval with a margin sometimes entire.
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External links photo of herbarium specimen at Missouri Botanical Garden, collected in México State in 1934